BAGHDAD — A suicide bomber detonated his explosive belt in a tent packed with mourners for the funeral for a Shiite tribal leader in the Iraqi city of Baqouba Monday, killing at least 15 people and wounding 40, officials said.

The blast came after a particularly bloody week in which more than 100 people died in bombings across the country targeting a major Shiite pilgrimage.

A local politician said it appeared to be an attempt to reignite sectarian violence between Sunni and Shiite Muslims that killed thousands and pushed Iraq to the brink of civil war in 2006 and 2007. Baqouba is a former Sunni insurgent stronghold 60 kilometers (35 miles) northeast of the capital Baghdad in Diyala province. But the attack was in a Shiite area.

Provincial police spokesman Ghalib al-Karkhi said the bomber set off his explosives in the tent filled with mourners on the third and last day of the funeral for a leader of the Zubaidi Shiite tribe.

Faris al-Azzawi, a provincial health official, said the toll was at least 15 dead and 40 wounded.

An official blamed al-Qaida-allied Sunni militants.

“Absolutely this is the way of al-Qaida — targeting innocent people to ignite the sectarian unrest,” said Sadiq al-Husseini, head of the Diyala provincial council.

Diyala is one of the last provinces in Iraq where al-Qaida and its allies remain a strong threat. The province, which is sandwiched between Baghdad and Iran, is divided among Sunnis, Shiites and Kurds and has been a sectarian flashpoint for years.